A very interesting study was published online on August 30, 2007 at Science which reported the discovery of a bacterial genome within the genome of fruitfly Drosophila ananassae. The researchers apparently have identified 44 out the 45 genes from a bacterium within the genus Wolbachia within the fly's genome. More interesting is the fact that 28 of these genes are active within the fly's genome.
The author's note that gene sequencing programs may need to be revised, since most of these programs will throw out bacterial genes as mere contaminants.
The big thing that strikes me about this study is the evolutionary adaptation aspect. It seems quite amazing to me that species are able to incorporate entire genes (let alone entire genomes) within their genomes for evolutionary advantages.
To read more about this study...
Link here -
Bacterial genome found within a fly's - DNA transfer from bacteria to animals is more common than thought.
By Ewen Callaway
Original Reference -
Julie C. Dunning Hotopp, et al. Widespread Lateral Gene Transfer from Intracellular Bacteria to Multicellular Eukaryotes. Science, Published Online August 30, 2007. DOI: 10.1126/science.1142490
Although common among bacteria, lateral gene transferthe movement of genes between distantly related organismsis thought to occur only rarely between bacteria and multicellular eukaryotes. However, the presence of endosymbionts, such as Wolbachia pipientis, within some eukaryotic germlines may facilitate bacterial gene transfers to eukaryotic host genomes. We therefore examined host genomes for evidence of gene transfer events from Wolbachia bacteria to their hosts. We found and confirmed transfers into the genomes of 4 insect and 4 nematode species that range from nearly the entire Wolbachia genome (>1 megabase) to short (<500 base pairs) insertions. Potential Wolbachia to host transfers were also detected computationally in three additional sequenced insect genomes. We also show that some of these inserted Wolbachia genes are transcribed within eukaryotic cells lacking endosymbionts. Therefore, heritable lateral gene transfer occurs into eukaryotic hosts from their prokaryote symbionts, potentially providing a mechanism for acquisition of new genes and functions.